As semiconductor manufacturers continue to reduce the thickness of devices, existing technologies are inadequate for solving the manufacturing challenges associated with procedures for making smaller devices. Emerging products, such as radio-frequency identification tags, sophisticated chip cards, and high-density memory devices, along with the advent of new and advanced packaging technologies for a variety of products such as micro-devices and sensors, require increasingly thinner wafers for the microfabrication of integrated circuits. While such thin wafers (e.g. 20-100 μm) exhibit increased flexibility, which in some cases is actually desired, they also exhibit increased fragility. The lack of adequate mechanical support and the increased fragility of thin wafers present major challenges to maintain high yield production in volume manufacturing environments.
Temporary bonding and debonding techniques, utilizing temporary bonding adhesives with a carrier or support wafer to provide mechanical support for a device wafer, is one approach in processing thin wafers. Published patent application US2012/0175045 discloses a solvent-based temporary bonding adhesive composition consisting of a vinyl T-containing polymer, a SiH containing crosslinker, a Pt catalyst, and an organic solvent with boiling point of less than 220° C. Published patent application US2011/0136321 and U.S. Pat. No. 7,541,264 disclose a silicone pressure-sensitive adhesive (PSA) approach. Zussman et al. (J. Microelectronics and Electronic Packaging, 2010, 7, 214-219) discloses an organic polymer such as polyimide as temporary bonding adhesives. Published PCT application WO2012/118700 describes a temporary bonding adhesive technology involving a two-layer material approach: a silsesquioxane resin based release layer and a polydimethylsiloxane based adhesive layer.
Alternative temporary bonding adhesives are needed to provide reliable and easy debonding while at the same time enable safe handling and processing of thin wafers. Such alternative temporary bonding adhesives must also be compatible with existing equipment lines and manufacturing processes.